Disposal: Science and Theory

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2 Gassing is a preferred and available option Whole house gassing Partial house gassing Containerized gassing Foam depopulation Foam with inert gas Foam without inert gas Individual depopulation Current Depopulation Techniques

3 Carbon dioxide (CO 2 ) one of the standard gassing procedures Suitable for field and laboratory Established anesthetic effect Birds unconscious during later phases Irritant at higher concentrations Faster increasing concentration decrease sensitivity time Carbon Dioxide Gassing

4 Argon-CO 2 gas depopulation evaluated under laboratory conditions Oxygen displacer Increased difficulty in field applications Thought to be more humane Disadvantages Requires extremely high concentrations to be effective Human hazard Rigid gas concentration control Ryan et al., 2006 Ar-CO 2 Gassing

5 Whole house gas procedure Seal the house Inject large volumes of gas Monitor gas concentration Suited for tight housing styles Reduce gas loss Sealing can be difficult with some designs Requires large volumes of gas Gas injection lance securely fastened Can force virus and particles outside the house Particles being forced out of the house by overpressure. Whole House Gassing

6 Whole house CO 2 used on ~1/2 of farms Mostly for chickens and turkeys farms Only able to achieve 40% concentration Took ~35 min before birds start to die Costly Gas supply in Netherlands Whole House - Netherlands 2003

7 Sealing required Doors/fans/vents HP liquid CO 2 May cause temperature stress Set up time ~1 hr CO 2 gas existed building in ~15 min Developing a manifold system for faster gas delivery to reduce time to death Sealing Canadian poultry house. Whole House Canada 2004

8 Broiler breeder facility 12,000 end of lay birds House preparation Vents and openings sealed Birds excluded from discharge area CO 2 injection ton CO 2 in 40 min min to reach 20% CO 2 Temperature drop Conscious birds -5.8 C Overall drop -42 C Ryan et al. (2006) Whole House Ireland 2006

9 Four empty turkey breeder houses Lance injection, 40 min Sealing required, 3.5 hr 40% or greater CO 2 concentration Closed vents 5.5 Tons CO 2 Open vents 16.5 Tons CO 2 Considerable losses Wrigley et al. (2008) Whole House Ireland 2008

10 Used mostly for broiler breeders Birds confine to ends of house or scratch area. Seal-off or cover birds with polyethylene and introduce CO 2 Broiler breeders sealed with polyethylene. Partial House

11 Multiple approaches for partial house gassing Portable panels Used for ducks and turkeys Panels on both sides of house Litter removed Birds driven to one end Chamber created Portable panel system in use with turkeys. Portable Panels

12 Specific type of partial house gassing used on Delmarva (2004) Suitable for broilers Carcasses remain in house Commonly available equipment Disadvantages Labor intensive Requires knowledge and skill Contaminated polyethylene Not compatible with all housing styles Preparing to cover the birds. Contaminated polyethylene being removed. Polyethylene Tent Method

13 P L A S T I C S H E E T P L A S T I C S H E E T L i t t e r L i t t e r C O 2 C O 2 C O 2 Litter Litter Litter Litter Polyethylene Tent Procedure

14 Fasten or staple plastic to ceiling Polyethylene Tent Method

15 Mark cylinder location Install CO 2 Cylinders (1 per 15.2 m) Polyethylene Tent Method Nozzle parallel to floor

16 Polyethylene Tent Method

17 Polyethylene Tent Method

18 Advantages Minimum equipment and cost Readily available supplies Carcasses not removed Disadvantages Labor intensive (15 20 people per house) Polyethylene removal and disposal Trained personnel required Welfare concerns Difficult to implement in pole-type houses Polyethylene Tent Method

19 Birds hand caught Loading crate placed in chamber Gas injected into chamber Good control of gas Flexible and versatile because of human catchers Loading crate and gassing container Containerized Gassing

20 Induce handling stress Time and labor intensive Potential for high virus exposure Biosecurity risk Limits disposal options DEFRA (UK) containerized gassing unit Containerized Gassing

21 Portable trailer unit Containers on trailer Gas supply preconnected Birds brought to trailer Small scale or backyard flocks Containerized Gassing

22 Containerized methods used for layers Requires 8 man crew (catchers, dumper, foreman) with 2 carts Euthanize 25 birds at a time, cart holds 200 birds Labor intensive, slow process and costly. Containerized Gassing

23 Portable container system developed in Canada Skid steer mounted Plastic bin, CO 2 cylinder, vaporizer and propane tank. Catchers can load 640 birds/12 minutes (~2900 birds/hr if dump next to bin) Containerized Gassing

24 Place ~60 layers in CO 2 charged cans. Cans may be slightly faster than carts Cans readily available in an emergency. Labor intensive and slow CO 2 source not with can Modified Atmosphere Kill Cans

25 Advantages Good control of gas concentration Commercially available or services provided Type of housing not an issue Disadvantages Labor intensive Induces handling stress Remove birds from houses (biosecurity risk) Mobile Systems

26 Personal protective equipment essential Protective suit, gloves, hair covering, goggles, N95 or greater, boots Increases difficulty of operation Decreases endurance and performance For any gassing operation SCBA-equipped personnel enter the house Monitor environment until CO 2 (<5000 ppm) and O 2 levels (>19.5%) are safe Operator equipped with SCBA for entering a gassed poultry house. Personal Protective Equipment

27 Will there be adequate workers to respond to an AI outbreak? Oversight of Workers